The present invention relates, in general, to golf equipment and, more particularly, to measuring the loft angle, the lie angle, or both the loft and lie angles of a golf club.
Fitting golf clubs to an individual golfer includes the consideration of several factors such as grip size, shaft length, swing weight, and loft and lie angular relationships of the golf clubs.
The loft angle of a golf club measured at its proper address position is the angle between a vertical plane and a plane that includes the face of the club head. Golf clubs having small loft angles are typically used for low trajectory-long distance golf shots, whereas golf clubs with large loft angles are typically used for high trajectory-short distance golf shots. The particular loft angle for each club in a set of golf clubs is not regulated by any standards or non-variable factors. Instead, the loft angles are normally predetermined by the designer of the clubs to achieve the desired performance characteristics for each club. The loft angles of the clubs are checked and may be adjusted by bending the clubs as needed to bring them into conformity with the manufacturer's predetermined angular values or to satisfy special requests that a golfer may make.
The lie angle of a golf club measured at its proper address position is the angle between the shaft axis and a line tangent to the center point on the sole of the club head. If the lie angle is too small for a particular golfer, the club head will be angled upwardly as it impacts a golf ball and may “hook” the golf ball to the left. Similarly, if the lie angle is too large for a particular golfer, the club head will be angled downwardly as it impacts a golf ball and may “fade” the golf ball to the right. The correct lie angle for an individual golfer is ideally determined by a trained fitting specialist, such as a Professional Golfer's Association (“PGA”) professional, who watches the golfer's swing and can determine the correct lie angle by observing, among other things, the flight of the golf ball.
With properly fitted golf clubs, an individual golfer should be able to achieve optimum performance and shot reliability in accordance with his or her skill level. However, golf clubs can be knocked out of adjustment or the golfer's swing characteristics can change. When this occurs, the golfer's performance level will deteriorate and in many instances, the golfer will not realize that the golf clubs are at fault. Therefore the loft and lie angles of golf clubs should be periodically checked and adjustments made if needed.
When checking or making changes in the loft and lie angles of golf clubs either at the time of manufacture or during subsequent adjustments, the clubs are usually placed one at a time in a special holding fixture that is part of a bench mounted measurement and adjustment mechanism. Such mechanisms usually make accurate measurements and provide visual indications of the loft and lie angles of the club being held in the fixture. With the club still in the holding fixture, special tools are used to bend the club head into the desired angular relationships. However, such bench mounted measurement and adjustment mechanisms cannot be considered portable and only manufacturing or large well-equipped golf shops can justify the cost or dedicate the space required by these mechanisms.
Although portable gauges for measuring loft and lie angles have been available, they have been of limited benefit because they typically measure the loft and lie angles when the golfer is holding the club rather than the actual angular relationships of the golf clubs.